Levels of lipid peroxides in uncomplicated pregnancy: a review of the literature.

The literature on lipid peroxide levels in uncomplicated pregnancy is limited, but some reasonable conclusions are possible. Despite the lack of precision in the predominant measure of lipid oxidation, there is agreement across a large number of studies that the level of lipid peroxides in blood is generally higher in pregnant women than in nonpregnant women. During gestation, elevations appear by the second trimester and may taper off later in gestation, decreasing further after delivery. Lipid peroxides also are produced in placenta, but their pattern of change over the course of pregnancy is unclear. Lipid peroxides are important because their uncontrolled production can result in oxidative stress, with significant damage to cell integrity. There is a growing literature that associates oxidative stress with preeclampsia, a major cause of maternal and fetal morbidity. The higher levels of lipid peroxides seen in blood and the production of lipid peroxides in the placenta, even in uncomplicated pregnancies, make new baseline studies a priority. These studies should include measurements of lipids and blood volume, because they can influence marker values, with sensitive and specific measures of lipid peroxidation made at various points of gestation. From our review of the existing literature we conclude that the importance of oxidative stress in reproduction is just beginning to be appreciated and studied.